A meeting of the world's richest oil exporters in Qatar ended on Sunday without an agreement. The meeting's aim was to strike a deal to freeze production in an effort to boost crude prices. However, after hours of talks, Qatar's Energy Minister Mohammed bin Saleh al-Sada said members of the Organization of the Petroleum Exporting Countries (OPEC) needed "more time." As a result, oil prices tumbled in Asian trading, with the price of both U.S. and London crude oil dropping more than 5 percent. The news comes as tensions continue to rise between OPEC members Saudi Arabia and Iran, which decided not to sent a representative to the talks late Saturday. Iranian Oil Minister Bijan Namdar Zangeneh said on state television that it didn't make sense to send someone from the Islamic Republic "as we are not part of the decision to freeze output." The next OPEC meeting is set to take place in June.